Devices can use global positioning system (GPS) as a method for obtaining location information. In such cases, devices receive a modulated signal transmitted from a satellite, and estimate location by positioning calculation. However, it is difficult for the device to estimate location information when the device is indoors, where reception of the radio waves transmitted by the GPS satellite is difficult.
For example, one method for overcoming such a problem is disclosed in non-patent literature (NPTL) 1. As disclosed in NPTL 1, there is a method by which the device uses radio waves transmitted from an access point in a wireless local area network (LAN) to estimate location.